A sheet handling device for receiving a flow of successive sheets of individual blanks from a sheet processing apparatus, collecting the sheets into pairs of superimposed sheets and discharging each pair into a further processing machine at a reduced speed. In addition, the device can handle the individual rows of blanks, which are produced in the sheet processing apparatus, by collecting the individual rows of blanks and superimposing them with other rows of blanks to form pairs of rows which are discharged at a reduced speed.
A sheet handling device, which was adapted to be located between a carton blank processing apparatus which produces a sheet of interconnected carbon blanks and a delivery unit which will separate the sheet of interconnected blanks into individual blanks was disclosed in my copending U.S. patent application, Ser. No. 127,142, filed Mar. 4, 1980, which is incorporated herein by reference thereto. In this device, the carton blank processing machine such as a platen press will preform the steps of cutting and creasing blanks in a sheet of blanks, stripping the waste materials from the sheet and then deliver the sheet of stripped interconnected blanks for further processing. In such a device, the speed of the platen press is faster than the device which receives the stripped sheet of interconnected blanks and proceeds to separate the sheets into individual blanks or to further process the blanks. The sheet handling device of the above mentioned application acts as a collecting device which will reduce the speed of the sheets and will deposit a sheet of blanks in a flow of sheets on the next following sheet prior to exiting or being discharged from the device. For this device to operate, each of the sheets must have the individual die cut blanks held together by nicks to ensure that the entire sheet of blanks remains together during transport through the device.
In certain instances, particularly when the final carton being formed from the die cut blank cannot tolerate rough edges formed by nicks, the die cut sheet will have nicks which are so weak that they cannot hold the blanks together under the stresses that occur in the direction of transport or the sheet will be completely separated without any nicks to hold the blanks together in the direction of transport. Thus, the blanks exiting the processing device will be either weakly held together blanks which will pull apart along the transport direction or individual rows of cartons which are separated from the next adjacent rows of cartons of the same sheet. The above mentioned sheet handling device cannot be used in a collecting mode to collect the individual carton blanks or rows of carton blanks which are separate from the following carton blanks or row of blanks of the sheet when taken in the direction of transport. It should be noted that the sheet handling device does not create any substantial forces or stresses in the interconnected blank in a direction transverse to the transport direction. Thus the weak nicks between adjacent cartons in a direction transverse to the transport direction are still sufficiently strong enough to hold the carton blank together as they are carried by the sheet handling device.